#include <stdio.h>

struct Books
{
  char title[50];
  char author[50];
  char subject[100];
  int book_id;
} book = {"C 语言", "RUNOOB", "编程语言", 123456};

int main()
{
  printf("title : %s\nauthor: %s\nsubject: %s\nbook_id: %d\n", book.title, book.author, book.subject, book.book_id);
  return 0;
}

// gcc -o structures.cpp structures.c && ./structures.cpp